Photoluminescence (PL) spectra of the GaInNAs/GaAs single quantum well (SQW) with different N compositions are carefully studied in a range of temperatures and excitation power densities. The anomalous S-shape temperature dependence of the PL peak is analysed based on the competition and switching-over between the peaks related to N-induced localized states and the peak reIated to interband excitonic recombination. It is found that with increasing N composition, the localized energy increases and the tuing point of the S-shape temperature dependence occurs at higher temperature, where the localized carriers in the bandtail states obtain enough thermal activation energy to be dissociated and delocalized. The rapid thermal annealing (RTA)effectively reduces the localized energy and causes a decrease of the switching-over temperature.